Geology topics
Research about Charleston, South Carolina
Source-linked reports with geographic coverage including Charleston, South Carolina.
Geology, hydrogeology, and potential of intrinsic bioremediation at the National Park Service Dockside II site and adjacent areas, Charleston, South Carolina, 1993-94
A long history of industrial and commercial use of the National Park Service property and adjacent properties located in downtown Charleston, South Carolina, has caused extensive contamination of the shallow subsurface soils and water-table aquifer. The National Park Service property is located adjacent to a former manufactured-gas plant site, which is the major source of the contamination. Contamination of this shallow water-table aquifer is of concern because shallow ground water discharges to the Cooper River and contains contaminants, which may affect adjacent wildlife or human populations. The geology of the National Park Service property above the Ashley Formation of the Cooper Group consists of two Quaternary lithostratigraphic marine units, the Wando Formation and Holocene deposits, overlain by artificial fill. The Wando Formation overlies the Ashley Formation, a sandy calcareous clay, and consists of soft, organic clay overlain by gray sand. The Holocene deposits are composed of clayey to silty sand and soft organic-rich clay. The artificial fill, which was placed at the site to create dry land where salt marsh existed previously, is composed of sand, silt, and various scrap materials. The shallow hydrogeology of the National Park Service property overlying the Ashley Formation can be subdivided into two sandy aquifers separated by a leaky, black, organic-rich clay. The unconfined upper surficial aquifer is primarily artificial fill. The lower surficial aquifer consists of the Wando sand unit and is confined by the leaky organic-rich clay. Aquifer tests performed on the wells screened in these aquifers resulted in hydraulic conductivities from 0.1 to 10 feet per day for the upper surficial aquifer, and 16 feet per day for the lower surficial aquifer. Vertical hydraulic gradients at the site are typically low. A downward gradient from the upper surficial aquifer to the lower surficial aquifer occurs throughout most of the year. A brick-lined storm-water-drainage archway located in the study area is a conduit for the overflow of seawater into the surficial aquifer during exceptionally high tides. The efficiency of intrinsic bioremediation to reduce contaminant migration in the upper surficial aquifer at the National Park Service site was assessed to determine if, and at what concentrations, contaminants are being transported to the Cooper River. This assessment required incorporating hydrologic, geochemical, microbiologic, and demographic information into a predictive solute-transport model to determine rates of contaminant transport to the Cooper River. The transport of toluene and naphthalene was modeled as a surrogate for the transport of aromatic and other hydrocarbon compounds at the study area. Laboratory estimates of the adsorption coefficients for sediments of the upper surficial aquifer suggest preferential adsorption of naphthalene over toluene. The adsorption coefficient of naphthalene is at least two orders of magnitude greater than that determined for toluene. Laboratory microbial-biodegradation experiments indicate that microorganisms present in the shallow aquifer have the potential to degrade toluene under anaerobic and aerobic conditions, and naphthalene primarily under aerobic conditions. Rates of microbial biodegradation are similar for both compounds under aerobic conditions. Flow-model calibration to the January 1994 water-table surface of the upper surficial aquifer was achieved by specifying appropriate hydrogeologic boundary conditions and using hydraulic conductivity values determined in the field. The brick-lined storm-water drainage archway located in the study area was modeled to account for ground-water discharge through this drain. An exploratory modeling approach was used to evaluate the range of possible solutions that approximate the transport of contaminants to the observed distributions. Approximate toluene solute-transport conditions for January 1994 were estimated using velocity dist
Simulation of water level, streamflow, and mass transport for the Cooper and Wando rivers near Charleston, South Carolina, 1992-95
The one-dimensional, unsteady-flow model, BRANCH, and the Branched Lagrangian Transport Model (BLTM) were calibrated and validated for the Cooper and Wando Rivers near Charleston, South Carolina. Data used to calibrate the BRANCH model included water-level data at four locations on the Cooper River and two locations on the Wando River, measured tidal-cycle streamflows at five locations on the Wando River, and simulated tidal-cycle streamflows (using an existing validated BRANCH model of the Cooper River) for four locations on the Cooper River. The BRANCH model was used to generate the necessary hydraulic data used in the BLTM model. The BLTM model was calibrated and validated using time series of salinity concentrations at two locations on the Cooper River and at two locations on the Wando River. Successful calibration and validation of the BRANCH and BLTM models to water levels, stream flows, and salinity were achieved after applying a positive 0.45 foot datum correction to the downstream boundary. The sensitivity of the simulated salinity concentrations to changes in the downstream gage datum, channel geometry, and roughness coefficient in the BRANCH model, and to the dispersion factor in the BLTM model was evaluated. The simulated salinity concentrations were most sensitive to changes in the downstream gage datum. A decrease of 0.5 feet in the downstream gage datum increased the simulated 3-day mean salinity concentration by 107 percent (12.7 to 26.3 parts per thousand). The range of the salinity concentration went from a tidal oscillation with a standard deviation of 3.9 parts per thousand to a nearly constant concentration with a standard deviation of 0.0 parts per thousand. An increase in the downstream gage datum decreased the simulated 3-day mean salinity concentration by 47 percent (12.7 to 6.7 parts per thousand) and decreased the standard deviation from 3.9 to 3.4 parts per thousand.
Stratigraphic framework for geologic and geohydrologic studies of the subsurface Cretaceous section near Charleston, South Carolina
No abstract available.
Retention time simulation for Bushy Park Reservoir near Charleston, South Carolina
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Aerobic biodegradation potential of subsurface microorganisms from a jet fuel-contaminated aquifer
In 1975, a leak of 83,000 gallons (314,189 liters) of jet fuel (JP-4) contaminated a shallow water-table aquifer near North Charleston, S.C. Laboratory experiments were conducted with contaminated sediments to assess the aerobic biodegradation potential of the in situ microbial community. Sediments were incubated with 14 C-labeled organic compounds, and the evolution of 14 CO 2 was measured over time. Gas chromatographic analyses were used to monitor CO 2 production and O 2 consumption under aerobic conditions. Results indicated that the microbes from contaminated sediments remained active despite the potentially toxic effects of JP-4. 14 CO 2 was measured from [ 14 C]glucose respiration in unamended and nitrate-amended samples after 1 day of incubation. Total [ 14 C]glucose metabolism was greater in 1 mM nitrate-amended than in unamended samples because of increased cellular incorporation of 14 C label. [ 14 C]benzene and [ 14 C]toluene were not significantly respired after 3 months of incubation. With the addition of 1 mM NO 3 , CO 2 production measured by gas chromatographic analysis increased linearly during 2 months of incubation at a rate of 0.099 μ mol g -1 (dry weight) day -1 while oxygen concentration decreased at a rate of 0.124 μ mol g -1 (dry weight) day -1 . With no added nitrate, CO 2 production was not different from that in metabolically inhibited control vials. From the examination of selected components of JP-4, the n -alkane hexane appeared to be degraded as opposed to the branched alkanes of similar molecular weight. The results suggest that the in situ microbial community is active despite the JP-4 jet fuel contamination and that biodegradation may be compound specific. Also, the community is strongly nitrogen limited, and nitrogen additions may be required to significantly enhance hydrocarbon biodegradation.
Studies related to the Charleston, South Carolina, earthquake of 1886: Neogene and Quaternary lithostratigraphy and biostratigraphy
No abstract available.
The 1886 Charleston, South Carolina, earthquake — A 1986 perspective
No abstract available.
Site of Charleston earthquakes pinned down?
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Geologic evidence for recurrent moderate to large earthquakes near Charleston, South Carolina
Multiple generations of earthquake-induced sand blows in Quaternary sediments and soils near Charleston, South Carolina, are evidence of recurrent moderate to large earthquakes in that area. The large 1886 earthquake, the only historic earthquake known to have produced sand blows at Charleston, probably caused the youngest observed blows. Older (late Quaternary) sand blows in the Charleston area indicate at least two prehistoric earthquakes with shaking severities comparable to the 1886 event.
Field studies of earthquake-induced, liquefaction-flowage features in the Charleston, South Carolina, area: Preliminary report
No abstract available.
Aeroradioactivity maps in heavy-mineral exploration: Charleston, South Carolina, area
No abstract available.
Uranium and phosphate resources in the Cooper Formation of the Charleston region, South Carolina
Phosphate deposits formerly exploited in the Charleston district were formed by weathering and reworking of the Cooper Formation (Eocene and Oliogcene). Previous workers have shown that unusual concentrations of uranium occur in phosphate-rich nodular material formed during subareal weathering. We found that the old mining district is on an erosional high of the Cooper Formation and in a topographic depression, but that the process of weathering enrichment of the Cooper Formation extends beyond the mining district. Fresh sediments from the Cooper Formation average 14.5 ppm uranium and 1.0 percent P 2 0 5 for Oliogcene samples and 5.6 ppm U and 0.15 percent P 2 0 5 for Eocene samples. Zones of secondary enrichment over undifferentiated Cooper Formation average 2 m thick and have average values of 60 ppm U and 5.4 percent P 2 0 5 . No deposits clearly of economic importance were found, although detailed studies may reveal such deposits.
Schlumberger electric soundings in the Charleston, S.C. earthquake area
No abstract available.
Studies related to the Charleston, South Carolina, earthquake of 1886: A preliminary report
PART A: The seismic history of the southeastern United States is dominated by the 1886 earthquake near Charleston, S.C. An understanding of the specific source and the uniqueness of the neotectonic setting of this large earthquake is essential in order to properly assess seismic hazards in the southeastern United States. Such knowledge will also contribute to the fundamental understanding of intraplate earthquakes and will aid indirectly in deciphering the evolution of Atlantic-type continental margins. The 15 chapters in this volume report on the first stage of an ongoing multidisciplinary study of the Charleston earthquake of 1886. The Modified Mercalli intensity for the 1886 earthquake was X in the meizoseismal area, an elliptical area 35 by 50 km, the center of which was Middleton Place. Seismic activity is continuing today in the Middleton Place-Summerville area at a higher level than prior to 1886. The present seismicity is originating at depths of 1 to 8 km, mostly in the crystalline basement beneath sedimentary rocks of the Coastal Plain. The crystalline basement beneath the Charleston-Summerville area is not simply a seaward extension of crystalline rocks of the Appalachian orogen that are exposed in the Piedmont to the northwest, but has a distinctive magnetic signature that does not reflect Appalachian orogenic trends. The area underlain by this distinctive geophysical basement, the Charleston block, may represent a broad zone of Triassic and (or) Jurassic crustal extension formed during the early stages of the opening of the Atlantic Ocean. The Charleston block is characterized in part by prominent, roughly circular magnetic and gravity highs that are thought to reflect maflc or ultramafic plutons. A continuously cored borehole put down over the shallowest (about 1.5 km deep) of these magnetic anomalies on the edge of the meizoseismal area bottomed at 792 m in amygdaloidal basalt. Although the K-Ar ages of about 100 m.y. for the basalt are consistent with the Late Cretaceous (Cenomanian) age of the overlying Cape Fear Formation, this must be a minimum age as a result of chemical alteration. The interpreted magmatic composition of the basalt most closely resembles the high-Ti quartz-normative tholeiites of Late Triassic and Early Jurassic age from eastern North America; age of the basalt is probably similar. Various geophysical surveys suggest that Coastal Plain sedimentary rocks do not simply dip homoclinally to the southeast on a gently dipping basement surface but are disturbed by structures not yet clearly deciphered. The present stress regime of the Charleston-Summerville area appears to be one of NE-SW. compression rather than of extension as it presumably was in the Mesozoic. The present stress regime seems similar to that of much of the eastern United States. Comparison of several seismic source areas in eastern North America shows that epicenters are typically near the periphery of positive gravity features interpreted to represent mafic or ultramafic bodies. Earthquakes may be caused by the concentration of regional stress around the peripheries of these inhomogeneities in an otherwise more homogeneous plate. Whether the inhomogeneities are more or less rigid than the. surrounding material is uncertain. PART B: In 1889, C. E. Dutton published all his basic intensity data for the 1886 Charleston, S.C., shock but did not list what intensity values he assigned to each report, nor did he show the distribution of the locations of these data reports on his isoseismal map. The writer and two other seismologists have each independently evaluated Dutton's 1,300 intensity reports (at least two of the. three interpreters agreed on intensity values for 90 percent of the reports), and the consensus values were plotted and contoured. One map was prepared on which contours emphasized the broad regional pattern of effects (with results similar to Dutton's) ; another map was contoured to depict the more
Uranium and phosphate resources in Cooper Formation in the Charleston region, South Carolina
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Heat flow near Charleston, South Carolina
As part of a study of the geology and geophysics of the Charleston, South Carolina, area, thermal conductivity, thermal gradient, and heat flow were determined in a 742 meter, continuously cored, test hole. The hole is located 41 km west-northwest of Charleston near Clubhouse Corners, Figure 1, directly over a gravity and magnetic high and the possible hypocenter of the 1889 Charleston earthquake. Drilling began January 13, 1975, and the hole penetrated 750 meters of Cenozoic and Upper Cretaceous sedimentary rocks finally bottoming in 42 meters of amygdaloidal basalts. Core recovery was 70% in sedimentary formations and 100% in the basalts. Detailed systematic studies of the core and the area surrounding the borehole were presented at the Symposium: Geology and Geophysics of Charleston, South Carolina, Area, held at the annual meeting of the Northeastern and Southeastern sections of the Geological Society of America during the week of March 25-27, 1976. Results from the thermal study are summarized in this report.
Geophysical logs from a geologic test hole near Charleston, South Carolina
On March 2, 1975, the U.S. Geological Survey completed a series of geophysical well logs in the Charleston Project Deep Core Hole No. 1 located at Latitude 32° 53.2 'N and Longitude 80° 21 . 5'W in Dorchester County near Charleston, South Carolina. The land surface is at an elevation of 5.4 m (18 ft) above mean sea level. The total depth of the test hole is 793 m (2,600 ft) and the geophysical logs were recorded through fresh barite mud to the bottom. The deep geologic. test hole penetrated the entire section of Atlantic Coastal Plain sediments and extended about 40 m (130 ft) into basement rock composed of basalt flows. The purpose of the logging is to assist in the interpretation of the depositional environments, stratigraphy, structural, and geological history of the onshore and offshore areas surrounding Charleston, S.C. The purpose of this report is to make the uninterpretated geophysical recordings of the entire log suite publicly available . The logs available are shown in table 1, along with the operating depth intervals, total footage, scale, units of measure, combination log, and other pertinent data.